1. Field of the Invention
This invention relates to nickel base superalloys which have oxidation resistance, high, hot hardness and abrasion resistance. This invention also relates to composite blades for gas turbine engines.
2. Description of the Prior Art
The requirements of the application for which the present invention is intended is unique. For this reason, there does not appear to be a great deal of prior art which is directly pertinent to the present invention. U.S. Pat. No. 2,994,605 discloses a nickel base alloy containing 40-80% Ni, 10-25% Cr, 0.25-5% (Cb+Ta), 0.5-8% (Mo+W) and 0.25-3% Al. This alloy does not contain yttrium and the aluminum range is below that contemplated by the present invention. Further, the reference teaches columbium and tantalum as being equivalent and tungsten and molybdenum as being equivalent and these equivalences are not valid for the alloy of the present invention. U.S. Pat. No. 3,905,552 discloses the addition of about 0.1% Y to nickel base superalloys for improved forgeability. Yttrium in superalloys is also discussed in U.S. Pat. Nos. 3,516,826; 3,346,378 and 3,202,506.